METHOD OF MAKING A MULTI-CHANNEL TIME BASED SERVO TAPE MEDIA
A thin film magnetic recording head is fabricated by forming a substrate from opposing ferrite blocks which have a ceramic member bonded between them. This structure is then diced to form a plurality of columns, wherein each column has a ferrite/ceramic combination. Each column represents a single channel in the completed head. A block of ceramic is then cut to match the columned structure and the two are bonded together. The bonded structure is then cut or ground until a head is formed, having ceramic disposed between each channel. A ferrite back-gap is then added to each channel, minimizing the reluctance of the flux path. The thin film is patterned on the head to optimize various channel configurations.
1 . A multi-channel surface film magnetic recording head comprising:
a plurality of magnetically permeable columns, each column being divided into two parts by a substantially magnetically impermeable gap member, the gap member forming a sub-gap on a writing side of the head;
at least one magnetically impermeable barrier, located between and magnetically isolating the plurality of magnetically permeable columns from one another; and
a magnetically permeable thin film layer spanning at least a portion of the sub-gap and magnetically coupling the two parts of each column.
2 . The magnetic recording head of claim 1 , further comprising:
a plurality of magnetically permeable back-bars, wherein each magnetically permeable column has a back-bar coupled to it and the back-bar bypasses the magnetically impermeable gap member at one end of the magnetically permeable column.
3 . The magnetic recording head of claim 2 , wherein each back-bar is a substantially U shaped ferrite block.
4 . The magnetic recording head of claim 2 , further comprising:
a single coil wrapped about each of the back-bars.
5 . The magnetic recording head of claim 2 , further comprising:
a plurality of coils wherein each back-bar has a single coil wrapped about it
6 . The magnetic recording head of claim 1 wherein the magnetically impermeable barrier is ceramic.
7 . The magnetic recording head of claim 1 wherein the thin film layer is located over an entire upper surface of the recording head.
8 . The magnetic recording head of claim 1 wherein the thin film layer is located only over a portion of the recording head, the portion being the area between air bleed slots cut into the head.
9 . The magnetic recording head of claim 1 wherein the thin film layer has been removed in portions so as to magnetically isolate each of the magnetically permeable columns.
10 . A method of making a multi-channel surface film magnetic recording head, comprising:
forming a sub-gap substrate by bonding a ceramic member between two magnetically permeable blocks;
cutting the substrate to form a plurality of columns, wherein each column is divided by a portion of the ceramic member;
providing a ceramic block having a plurality of notches corresponding to the plurality of columns;
bonding the columns within the notches to form a head member;
processing the head member so that the head member has alternating sections of the ceramic and the columns with the columns extending therethrough;
coupling at least one winding to a first side of the columns; and
forming writing gaps in a second side of the columns.
11 . The method of claim 10 wherein bonding the columns within the notches includes:
providing glass within the notches;
heating the glass so as to melt the glass;
allowing the melted glass to wick between the notches and the columns; and
allowing the glass to cool thereby forming a bond.
12 . The method of claim 10 wherein processing the head member includes cutting a top and bottom portion of the head member to expose portions of the columns in both the top and bottom portion.
13 . The method of claim 10 wherein coupling a winding further includes;
coupling a back-bar to each of the columns; and
winding the coil about the back-bar.
14 . The method of claim 13 wherein the back-bar is formed from a continuous piece of magnetically permeable material.
15 . The method of claim 10 wherein forming writing gaps further includes:
forming a magnetically permeable surface thin film; and
creating gaps in the thin film.
16 . The method of claim 15 wherein the thin film is foamed over an entire upper surface of the head.
17 . The method of claim 15 wherein the thin film is only located between air bleed slots cut into the head.
18 . The method of claim 15 wherein the thin film is absent in strips between each column thereby magnetically isolating each column.
19 . A surface film magnetic recording head comprising:
a magnetically permeable core;
a substantially magnetically impermeable member dividing the core into two poles and forming a sub-gap;
a magnetically permeable thin film coupling the two poles across the sub-gap, wherein the thin film includes at least one writing gap; and
a back-bar, formed from magnetically permeable material, the back bar bypassing the impermeable member to complete a magnetic circuit between the two poles.
20 . The surface film magnetic recording head of claim 19 , wherein the core and back-bar are formed from ferrite.
21 .- 51 . (canceled)